/* ----------------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date:        15. February 2012
* $Revision: 	V1.1.0
*
* Project: 	    CMSIS DSP Library
* Title:		arm_float_to_q7.c
*
* Description:	Converts the elements of the floating-point vector to Q7 vector.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
*    Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
*    Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
*    Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
*    Documentation updated.
*
* Version 1.0.1 2010/10/05
*    Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
*    Production release and review comments incorporated.
* ---------------------------------------------------------------------------- */

#include "arm_math.h"

/**
 * @ingroup groupSupport
 */

/**
 * @addtogroup float_to_x
 * @{
 */

/**
 * @brief Converts the elements of the floating-point vector to Q7 vector.
 * @param[in]       *pSrc points to the floating-point input vector
 * @param[out]      *pDst points to the Q7 output vector
 * @param[in]       blockSize length of the input vector
 * @return none.
 *
 *\par Description:
 * \par
 * The equation used for the conversion process is:
 * <pre>
 * 	pDst[n] = (q7_t)(pSrc[n] * 128);   0 <= n < blockSize.
 * </pre>
 * \par Scaling and Overflow Behavior:
 * \par
 * The function uses saturating arithmetic.
 * Results outside of the allowable Q7 range [0x80 0x7F] will be saturated.
 * \note
 * In order to apply rounding, the library should be rebuilt with the ROUNDING macro
 * defined in the preprocessor section of project options.
 */


void arm_float_to_q7(
    float32_t* pSrc,
    q7_t* pDst,
    uint32_t blockSize)
{
	float32_t* pIn = pSrc;                         /* Src pointer */
	uint32_t blkCnt;                               /* loop counter */

#ifdef ARM_MATH_ROUNDING

	float32_t in;

#endif /*      #ifdef ARM_MATH_ROUNDING        */

#ifndef ARM_MATH_CM0

	/* Run the below code for Cortex-M4 and Cortex-M3 */

	/*loop Unrolling */
	blkCnt = blockSize >> 2u;

	/* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
	 ** a second loop below computes the remaining 1 to 3 samples. */
	while(blkCnt > 0u) {

#ifdef ARM_MATH_ROUNDING
		/* C = A * 128 */
		/* convert from float to q7 and then store the results in the destination buffer */
		in = *pIn++;
		in = (in * 128);
		in += in > 0 ? 0.5 : -0.5;
		*pDst++ = (q7_t)(__SSAT((q15_t)(in), 8));

		in = *pIn++;
		in = (in * 128);
		in += in > 0 ? 0.5 : -0.5;
		*pDst++ = (q7_t)(__SSAT((q15_t)(in), 8));

		in = *pIn++;
		in = (in * 128);
		in += in > 0 ? 0.5 : -0.5;
		*pDst++ = (q7_t)(__SSAT((q15_t)(in), 8));

		in = *pIn++;
		in = (in * 128);
		in += in > 0 ? 0.5 : -0.5;
		*pDst++ = (q7_t)(__SSAT((q15_t)(in), 8));

#else

		/* C = A * 128 */
		/* convert from float to q7 and then store the results in the destination buffer */
		*pDst++ = __SSAT((q31_t)(*pIn++ * 128.0f), 8);
		*pDst++ = __SSAT((q31_t)(*pIn++ * 128.0f), 8);
		*pDst++ = __SSAT((q31_t)(*pIn++ * 128.0f), 8);
		*pDst++ = __SSAT((q31_t)(*pIn++ * 128.0f), 8);

#endif /*      #ifdef ARM_MATH_ROUNDING        */

		/* Decrement the loop counter */
		blkCnt--;
	}

	/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
	 ** No loop unrolling is used. */
	blkCnt = blockSize % 0x4u;

	while(blkCnt > 0u) {

#ifdef ARM_MATH_ROUNDING
		/* C = A * 128 */
		/* convert from float to q7 and then store the results in the destination buffer */
		in = *pIn++;
		in = (in * 128);
		in += in > 0 ? 0.5 : -0.5;
		*pDst++ = (q7_t)(__SSAT((q15_t)(in), 8));

#else

		/* C = A * 128 */
		/* convert from float to q7 and then store the results in the destination buffer */
		*pDst++ = __SSAT((q31_t)(*pIn++ * 128.0f), 8);

#endif /*      #ifdef ARM_MATH_ROUNDING        */

		/* Decrement the loop counter */
		blkCnt--;
	}


#else

	/* Run the below code for Cortex-M0 */


	/* Loop over blockSize number of values */
	blkCnt = blockSize;

	while(blkCnt > 0u) {
#ifdef ARM_MATH_ROUNDING
		/* C = A * 128 */
		/* convert from float to q7 and then store the results in the destination buffer */
		in = *pIn++;
		in = (in * 128.0f);
		in += in > 0 ? 0.5f : -0.5f;
		*pDst++ = (q7_t)(__SSAT((q31_t)(in), 8));

#else

		/* C = A * 128 */
		/* convert from float to q7 and then store the results in the destination buffer */
		*pDst++ = (q7_t) __SSAT((q31_t)(*pIn++ * 128.0f), 8);

#endif /*      #ifdef ARM_MATH_ROUNDING        */

		/* Decrement the loop counter */
		blkCnt--;
	}

#endif /* #ifndef ARM_MATH_CM0 */

}

/**
 * @} end of float_to_x group
 */
